Grade-line indicator.



J. C. FRENCH.

GRADE LINE INDICATOR.

APPLICATION FILED SEPT.24. 19!?- 3 SHEETSSHEET I,

Patented Apr. 15,1919.

J. C. FRENCH.

GRADE LINE INDICATOR. APELICATION FILED sEPT.24. 1917.

Patented A r. 15,1919

3 SHEETS-SHEET 2- d QM J. C. FRENCH. GRADE LINE 1ND-ICATOR.

APPLICATION FILED SEPT.24. 1917- Patented Apr. 15, 1919.

3 SHEETSSHEET 3.

. cordance -wit thereby to "trench.

tion consists in matters hereinafter forward, and to run JAMES 0. Farms, or cmcaeo,

itmnorsyassiei ron 'ro rnnimmcx c. AUSTIN, or cmcaeo, rumors.

cmn nmr. INDICATOR.

. Specification of Letters Patent.

To all whom it may concern:

Be it known that I, JAMEs O. FRENCH, acitizen of'the United States of America, and resident of Chicago, have invented a certain new and useful Im-' provement tin Grade-Line Indicators, of which the following is a specification.

My invention relates to for excavators-1n general, but more particularly to those employed on trenching ma-.

the grade-line of the botwhile the machine is pass-' chines topreserve tom of the trench,

ing over hilly or uneven ground, and whereby the digging device at the rear of the trenching machine may beadjusted in acthe rise and fall or changes in position of the body of the excavator, keep the bottom of the trench level. v

Generally stated, the'object of my invention is to provide a novel and improved excavator grading device orgrade line indilook county, Illinois,

grading devices would be adepression cator which will'automatically indicate at all times the adjustment vice necessary to maintainthe predetermined grade line for the bottom of the It is also an object to provide certain debinations tending to increase the general efliof this particular character.

To these and other useful ends,

set forth and claimed.

In the accompanying drawings Figure 1 is a side elevation of a trenching machine provided with a grading device or grade line indicator embodying the-principles of my invention. T

Fig. 2 is a diagrammatic view of said excavator and grading device, in sideelevation, illustrating the method of operation thereof; Q r

Fig. 3v is an enlarged sideelevation of said grading'device.

Fig. 4' is a detail Fig. 3.

As thus 'illustrated,.my invention comprises a suitable body frame A mounted on caterpillar. traction devices B and. front section on line 4-4= in motor D to operate said traction devices to propel the machine of the digging demy inven-' to kn'ow'ata g Y of a laterally projecting.

on a pendulum 1 which ;'has' a bearing 2 by the excavating app ratus. Said apparatus comprisesa beam E mounted on a transverse shaft e, which latter is supported on a suitable frame a at the rear of the excavator body. An endless series of buckets sprocket chains f is suitably mounted on said digging beam and arranged to cut a trench by their upward movement as the machine -moves slowly forward in the usual and well the machine suddenly tilt upward, the result of the digging and conveying buckets at the rear end of the 'machine,vwith the result tha-t the bottom of from the the trench will be depressed away desired level or grade line thereof. Also, should the front end of the machine suddenly drop downward, the digging buckets at the rear of the machine will rise, and this will bring thebotztom of the ditch upward to a point higher than the level desired therefor. In the operation of a machine of this kind, therefore, it is the practice to change the angle of the digging beam E to meet the requirements, as the body of the machine .tilts upward or having been provided for assisting in such F mounted on. 7

while the shouldthe front end of- I downward at the forward end thereof, various arrangements Patented Apr. 15, 1919. Application niee'se tember 24, 1917, Seria1No.192,895.

adjustment. With the arrangements here- V tofore arranged for this purpose, however, itis not always possible to accurately adjust the digging apparatus, in a satisfactory manner. In some cases it has been diflicult or practically impossible to maintain the bottom of the ditch level or straight while the machine was passing over uneven surfaces of the round. ,With a view, therefore, to enablm the operator or attendant ance, at all times, whether the digging apparatus requires readjustment to bring the lower end-thereof back onto the grade line from the bottom ofthe trench, a

vertical and graduated indicating bar G is hung on the shaft. (2, through the medium frame g mounted which'it is swingingly supported on said shaft, the pendulum weight 3 serving to therefrom in opposite directions.

keep this entire Swinging structure in a vermanner shown. The zero mark is at the center of the series of graduations, in each case, and the gradu-ations are numbered ging beam-E isprovided with an adjustable curved bar 6, having a pointer 7 that travels on the circle of the graduations of the indicator 5, in a manner that will be readily understood. The bar 6, of course, is curved about the axis of the shaft 6, and is mounted in a bracket 8 on the beam E, so that the pointer 7 is adjustable on a circle struck from said axis.

The operation is as follows: The grade wire His strung on poles or posts above the ground, .in the direction desired for the trench, the depth of the trench below this grade line having been previously determined. The machine is started so that the line H is opposite zero on the indicator G, (see Fig. 3) and with the beam E adjusted by the device I (which may be of any known character) so that the pointer 7 is at zero on the indicator 5, when the digging apparatus is at the desired depth for the trench. The

.machine then moves forward, with the buck-. ets F operating in the customary manner.

So long asthe machine travels horizontally overlevel ground no adjustment of the dig-- ging apparatus will be necessary. Suppose, however, that the front end of the.machine tilts upward, as shown in Fig. 2, which would depress the lower end of the digging apparatus, and which would bring the bottom of the ditch or trench determined gra le line therefor. In such .case, the backward tilting of the frame a on v manner that will be readily understood, for

the pendulum weight 3 keeps the indicator G vertical and maintains the correct position for the indicator5 regardless of the position.

of the body of the excavator. The operator or attendant, observing that the grade line is not being maintained, will then operate the adjusting device I of the digging apparatus, which device is of any suitable orv well known character, as, for example, like those commonly used in trenchlng machines of this class, so that the lower end of the beam E will be tilted upward until 'the pointer ,7 is again opposite the zero mark on the indicator 5, as shown in dotted lines 5 in Fig. 2, which brings the lower end of the The digbelow the predigging apparatus into position to maintain the desired level of grade line for the bottom of the trench. Should the body of the excavator tilt in the opposite direction, thus raising the shaft 6, the beam E will thereby be tilted upward, and adjustment of the device I will be necessary to tilt the beam downward again, the amount of adjustment necessary for this purpose being determined by an inspection of the indicators G and 5 in a manner that will be readily understood. Sometimes, of course, in order to maintain the desired depth for the bottom of the trench, the pointer 7 must be raised or lowered relative to the zero mark on indicator 5, depending upon the number of degrees which the zero mark on indicator G is found to be either below or above the Wire H, which will be true in cases where the body of the machine, while traveling along, rises and falls and is found to be working at different heights relative to the wire H, but in a horizontal position. In other words, the body of the machine may be found to be working either higher or lower, but in a horizontal position, and with the pointer 7 opposite the zero mark on the indicator 5, but with the zero mark on the indicator G either above or below the grade wire H, and in such cases the beam E must be tilted until the pointer 7 is off center, so to speak, a

number of degrees corresponding to ,the

number of degrees that the wire H is off center (off the zero mark) on the indicator G,

depending upon the condition or charactermonly provided with means for lengthening and shortening the digging beam E, for

trenches of diiferent depths, and for this purpose the frame 4 can be providedwith a plurality of curved graduated plates, formed on circles of different diameters, as shown in Fig. 3, and the pointer 7 can'be made adjustable to enable it to cooperate with any of said graduated plates, depending upon the length of the digging beam.

Also, for the purpose of varying the depth of the trench, the curved bar dis adjustable in the bracket 8, so that the digging device can be set for any desired depth when the machine starts a trench. If the digging beam is raised, and the pointer 7 then brought back to zero, a trench of less depth will then be made. On the otherhand, if the digging beam is lowered and the pointer 5, a trench of greater ,depth will then be made as the machinemoves forward.

While the wire H is shown as the means for forming the grade line above ground, it

is obvious that any suitable means can be employed for this purpose, which will form either a continuous and tangible line, or which 7 then brought back to zero on the indicator. I

ranged so that the will form or determine an imaginary grade line, as, for example, by a series of posts aroperator or attendant can sight from one post to another, along the line a grade line,

of posts, and thus determine whether the zero mark of the indicator G is on the line. The invention is not limited to the exact construction shown and described.

What I claim as my invention is: 1. In a trenching machine provided with a digging device mounted to swing about a horizontal ,axis extending transversely of the trench, means above the ground to form an indicator on the machine to cooperate with said grade line to indicate the rise and fall of said axis when the machine travels over uneven ground, and means operated by pendulum action about a,hori zontal axis to determine the adjustment necessary for said digging device about said axis-to maintain the lower end thereof the desired distance below said grade line.

curve struck from said axis and 2". A structure. as specified in claim 1, said f indicator comprising a vertically graduated member hung from said axis .to swing pendulum-like thereon, and said means comprising one elementhavinggraduations on a another element mounted to cooperate therewith, one of said elements being rigid with said graduated member and the other being controlled 7 by said dlgging device.

3. A structure as speclfied in claim 1, said indicator comprising a member mounted to swing pendulum-like on said axis, and said means comprising an indicating element mounted to swing about said axis and controlled by said member.

4'. A structure as specified in claim 1, said indicator comprising a vertically graduated member mounted to swing pendulum-like about said axis, so that said member will remain vertical when the machine tilts upward or downward at the forward end thereof.

5. The combination of (1) .a trenching machine provided with a trench-cutter at the rear end thereof, (2) means for adjusting said trench-cutter about a horizontal .and transversely extendingaxis, to raise and lower the trench-cutter in the trench, (3) means at the side of the trench to form a horizontal axis to deteimgfie grade line by which to determine and maintain the desired depth of the trench, (4) means to propel the machine forward while said trench-cutter is in operation, (5) means cooperating with said grade line to indicate the rise and fall of'the machine relative thereto, while the machine is traveling over the surface of the ground in a direction parallel with said grade line, and (6) means operating about said axis to determine the adjustment of said trench-cutter necessary to maintain the lower end thereof the desired distance below said grade line.

6. In a trenching machine; the combination of an indicator to show the extent of up and down movement of the machine, a trench-cutter, means for adjusting said trench-cutter, and means oscillatory in avertical longitudinal plane about a horizontal axis to determine the extent of adjustment necessary for said trench-cutter to maintain the lower end'thereof at the desired depth in the ground.

7. In a trenching machine, the combination of a body provided with means to travel over the surface of the ground, a digging device tocut a trench while said body moves forward over the ground, means for changing the depthc' of said trench-cutterin the to maintain the lower end thereof at the desired depth in the ground.

' 8. In an adjustable trenching machine, the combination of graduated means to indicate the exact de ree of rise and fall of the machine,-and dev1ces arranged to swing in a vertical longitudinal plane about a transverse axis and cooperating with said means, and operative by pendulum action about a from time to 'ustment necestime the exact degree of .depth of the sary to maintain the desire trench.

Signed by me at Chicago, Cook county, Illinois, this 10th day of September, 1917.

JAMESC. FRENCH; 

